Lost C-v today #21150

This is a weird one. Today C-v (my most used vim shortcut. Or top 5 at least), causes a paste instead of entering Visual Block mode!

I had not changed my vimrc or anything other than rolling updates to my distro. I saw I pulled in vim-9.2.1001 last night. Easy, roll back, git bissect to find the bug. Well...

I built an older version (v9.2.0555 that i have around while I procrastinate on #17747) and it also happens there! So it may be my config files after all.

Starting with -u NONE 'solves' the issue. so it is indeed my config files.

But I haven't changed anything in months. Let's start with a blank file and add line by line. Here's the culprit:

map  <C-S-v> <MiddleMouse>
map! <C-S-v> <MiddleMouse>

(Git tells me those lines were added in 2025-01-29)

And it happens on both 9.2.0555 and 9.2.10001, but it only started today. Did something changed in my libs or environment? I don't see anything relevant installed between it starting. What should I even look for?

trying another combination shows the same thing:
map! <C-S-f> hello
and yes, just C-f inputs "hello" :(

(modifyOtherKeys should be irrelevant on gvim, right? also, it is not intercepting C-v because without that config line it reaches vim just fine)

I found some discussion on C-S-... mappings never being supported https://stackoverflow.com/questions/26334111/vim-c-s-key-mapping ...But I am pretty sure I had this working until recently (or at least, just not overriding C-v which is my most used combo -- I did use my custom C-S-v very rarely)

To wrap it, for now, I am happy this is the 'cause' and it is something I will not miss if I simply disable it. But why it happened today is driving me insane :)